A scroll compressor has been known as an example of a compressor which compresses fluid.
Japanese Unexamined Patent Publication No. 2012-202221 discloses a scroll compressor of this kind. The scroll compressor includes a compression mechanism having a fixed scroll and a movable scroll. The fixed scroll includes a disc-shaped end plate, a cylindrical outer peripheral wall standing on an outer edge of the end plate, and a spiral wrap standing inside the outer peripheral wall. The movable scroll includes an end plate which is in sliding contact with tip ends of the outer peripheral wall and wrap of the fixed scroll, and a wrap standing on the end plate. The compression mechanism forms a compression chamber between the two wraps when the fixed and movable scrolls mesh with each other. The volume of the compression chamber gradually decreases when the movable scroll is rotating eccentrically about the fixed scroll. As a result, fluid in the compression chamber is compressed.
In this scroll compressor, an oil groove (fixed scroll's oil groove) is provided in an end face of the outer peripheral wall of the fixed scroll, and an oil groove (movable scroll's oil groove) provided in the end plate of the movable scroll. A high pressure lubricating oil is fed to the fixed scroll's oil groove. In the compression mechanism, the movable scroll rotates eccentrically, thereby alternately switching between a first state where the movable scroll's oil groove communicates with the fixed scroll's oil groove, and a second state where the movable scroll's oil groove communicates with a fluid chamber (compression chamber). When the compression mechanism is in the first state, high pressure lubricating oil is fed from the fixed scroll's oil groove to the movable scroll's oil groove. The oil is used to lubricate a thrust surface of the outer peripheral wall of the fixed scroll and a thrust surface of the end plate of the movable scroll. When the compression mechanism is in the second state, high pressure lubricating oil is fed from the movable scroll's oil groove to the fluid chamber. This facilitates the lubrication of sliding portions of the wraps of the fixed and movable scrolls. In addition, a gap between the sliding portions is effectively sealed, thereby improving the compression efficiency.